Browsing by Subject "Galaxies"

Now showing items 1-20 of 87

    • Aligned metal absorbers and the ultraviolet background at the end of reionization 

      Doughty, Caitlin; Finlator, Kristian; Oppenheimer, Benjamin D.; Dave, Romeel; Zackrisson, Erik (Oxford University Press, 2018)
      We use observations of spatially-aligned C ii, C iv, Si ii, Si iv, and O i absorbers to probe the slope and intensity of the ultraviolet background (UVB) at z ∼ 6. We accom- plish this by comparing observations with ...

    • Black hole - galaxy correlations without self-regulation 

      Angles-Alcazar, Daniel; Ozel, Feryal; Dave, Romeel (American Astronomical Society, 2013)
      Recent models of black hole growth in a cosmological context have forwarded a paradigm in which the growth is self-regulated by feedback from the black hole itself. Here we use cosmological zoom simulations of galaxy formation ...

    • Breaking baryon-cosmology degeneracy with the electron density power spectrum 

      Nicola, Andrina; Villaescusa-Navarro, Francisco; Davé, Romeel (IOP Publishing, 2022)
      Uncertain feedback processes in galaxies affect the distribution of matter, currently limiting the power of weak lensing surveys. If we can identify cosmological statistics that are robust against these uncertainties, or ...

    • The bright extragalactic ALMA redshift survey (BEARS) – II. Millimetre photometry of gravitational lens candidates 

      Bendo, George; Urquhart, S. A.; Baker, Andrew J. (Oxford University Press, 2023)
      We present 101- and 151-GHz ALMA continuum images for 85 fields selected from Herschel observations that have 500-μm flux densities >80 mJy and 250–500-μm colours consistent with z > 2, most of which are expected to be ...

    • Calibrating photometric redshifts with intensity mapping observations 

      Alonso, David; Ferreira, Pedro G.; Jarvis, Matt; Moodley, Kavilan (American Physical Society, 2017)
      Imaging surveys of galaxies will have a high number density and angular resolution yet a poor redshift precision. Intensity maps of neutral hydrogen (HI) will have accurate redshift resolution yet will not resolve ...

    • Calibrating the James Webb Space telescope filters as star formation rate indicators 

      Senarath, Madhooshi R.; Brown, Michael J. I.; Cluver, Michelle E.; Moustakas, John; Armus, Lee; Jarrett, Thomas H. (American Astronomical Society, 2018)
      We have calibrated the 6.5m James Webb Space Telescope (JWST) mid-infrared (MIR) filters as star formation rate (SFR) indicators, using JWST photometry synthesized from Spitzer spectra of 49 low-redshift galaxies, which ...

    • Ceers key paper. I. An early look into the first 500myr of galaxy formation with jwst 

      Finkelstein, Steven L.; Bagley, Micaela B.; Davé, Romeel (American Astronomical Society, 2023)
      We present an investigation into the first 500 Myr of galaxy evolution from the Cosmic Evolution Early Release Science (CEERS) survey. CEERS, one of 13 JWST ERS programs, targets galaxy formation from z ∼ 0.5 to >10 using ...

    • Clustering of HI galaxies in the HI parkes all sky survey and arecibo legacy fast alfa survey 

      Passmoor, S. S.; Cress, Catherine; Faltenbacher, A (Oxford University Press, 2011)
      We investigate the clustering of H I-selected galaxies in the Arecibo Legacy Fast ALFA Survey (ALFALFA) and compare results with those obtained for the H I Parkes All Sky Survey (HIPASS). Measurements of the angular ...

    • Comparison of Hi and optical redshifts of galaxies - The impact of redshift uncertainties on spectral line stacking 

      Maddox, Natasha; Hess, Kelley M.; Blyth, S.-L.; Jarvis, Matt (Oxford University Press, 2013)
      Accurate optical redshifts will be critical for spectral co-adding techniques used to extract detections from below the noise level in ongoing and upcoming surveys for Hi, which will extend our current understanding of ...

    • The complex physics of dusty star-forming galaxies at high redshifts as revealed by Herschel and Spitzer 

      Lo Faro, Barbara; Franceschini, Alberto; Vaccari, M.; Silva, L.; Rodighiero, G.; Berta, S.; Bock, J.; Burgarella, D.; Buat, V.; Cava, A.; Clements, D.L.; Cooray, Asantha; Farrah, D.; Feltre, Anna; Gonzalez-Solares, Eduardo A.; Hurley, P.; Lutz, D.; Magdis, G.; Magnelli, B.; Marchetti, L.; Oliver, S.J.; Page, Matthew J.; Popesso, P.; Pozzi, F.; Rigopoulou, D.; Rowan-Robinson, M.; Roseboom, I.G.; Scott, Douglas; Smith, A.J.; Symeonidis, Myrto; Wang, L.; Wuyts, S. (IOP Publishing, 2013)
      We combine far-infrared photometry from Herschel (PEP/HerMES) with deep mid-infrared spectroscopy from Spitzer to investigate the nature and the mass assembly history of a sample of 31 luminous and ultraluminous infrared ...

    • The COS-Halos survey: Rationale, design and a census of circumgalactic neutral hydrogen 

      Tumlinson, Jason; Thom, Christopher; Dave, Romeel; Werk, Jessica K.; Prochaska, J. Xavier; Tripp, Todd M.; Katz, Neal; Oppenheimer, Benjamin D.; Meiring, Joseph D.; Ford, Amanda Brady; O'Meara, John M.; Peeples, Molly S.; Sembach, Kenneth R.; Weinberg, David H. (IOP Publishing, 2013)
      We present the design and methods of the COS-Halos survey, a systematic investigation of the gaseous halos of 44 z = 0.15–0.35 galaxies using background QSOs observed with the Cosmic Origins Spectrograph aboard the Hubble ...

    • Cosmology from HI galaxy surveys with the SKA 

      Maartens, Roy; Abdalla, Filipe B.; Bull, Philip; Camera, Stefano; Benoit-Levy, Aurelien; Joachimi, Benjamin; Kirk, Donnacha; Klöckner, Hans-Rainer; Raccanelli, Alvise; Santos, Mario G.; Zhao, Gong-Bo (Proceedings of Science, 2014)
      The Square Kilometer Array (SKA) has the potential to produce galaxy redshift surveys which will be competitive with other state of the art cosmological experiments in the next decade. In this chapter we summarise what ...

    • Cosmology on the largest scales with the SKA 

      Camera, Stefano; Raccanelli, Alvise; Bull, Philip; Bertacca, Daniele; Chen, Xuelei; Ferreira, Pedro G.; Kunz, Martin; Maartens, Roy; Mao, Yi; Santos, Mario G.; Shapiro, Paul R.; Viel, Matteo; Xug, Yidong (Proceedings of Science, 2014)
      The study of the Universe on ultra-large scales is one of the major science cases for the Square Kilometre Array (SKA). The SKA will be able to probe a vast volume of the cosmos, thus representing a unique instrument, ...

    • Cosmology on ultralarge scales with intensity mapping of the neutral hydrogen 21 cm emission: limits on primodial non-gaussianity 

      Camera, Stefano; Santos, Mario G.; Ferreira, Pedro G.; Ferramacho, Luis (American Physical Society, 2013)
      The large-scale structure of the Universe supplies crucial information about the physical processes at play at early times. Unresolved maps of the intensity of 21 cm emission from neutral hydrogen HI at redshifts z ~ 1 − ...

    • Cosmology with a SKA HI intensity mapping survey 

      Santos, Mario G.; Bull, Philip; Alonso, David; Camera, Stefano; Ferreira, Pedro G.; Bernardi, Gianni; Maartens, Roy; Viel, Matteo; Villaescusa-Navarro, Francisco; Abdalla, Filipe B.; Jarvis, Matt; Metcalf, R. Benton; Pourtsidou, A.; Wolz, Laura (Proceedings of Science, 2014)
      HI intensity mapping (IM) is a novel technique capable of mapping the large-scale structure of the Universe in three dimensions and delivering exquisite constraints on cosmology, by using HI as a biased tracer of the ...

    • A deep radio view of the evolution of the cosmic star formation rate density from a stellar-mass-selected sample in VLA-COSMOS 

      Malefahlo, Eliab D.; Jarvis, Matt J.; Santos, Mario G.; White, Sarah V.; Adams, Nathan J.; Bowler, Rebecca A. A. (Royal Astronomical Society, 2022)
      We present the 1.4 GHz radio luminosity functions (RLFs) of galaxies in the Cosmic Evolution Survey (COSMOS) field, measured above and below the 5σ detection threshold, using a Bayesian model-fitting technique. The radio ...

    • A deep search for faint galaxies associated with very low-redshift C iv absorbers: A case with cold-accretion characteristics 

      Burchett, Joseph N.; Tripp, Todd M.; Werk, Jessica K.; Howk, J. Christopher; Dave, Romeel; Prochaska, J. Xavier; Ford, Amanda Brady (The American Astronomical Society, 2013)
      Studies of QSO absorber–galaxy connections are often hindered by inadequate information on whether faint/dwarf galaxies are located near the QSO sight lines. To investigate the contribution of faint galaxies to QSO ...

    • Disentangling non-gaussianity, bias, and general relativistic effects in the galaxy distribution 

      Bruni, Marco; Crittenden, Robert; Maartens, Roy (American Physical Society, 2012)
      Local non-Gaussianity, parametrized by f NL , introduces a scale-dependent bias that is strongest at large scales, precisely where general relativistic (GR) effects also become significant. With future data, it should ...

    • Einstein's legacy in galaxy surveys 

      Camera, Stefano; Maartens, Roy; Santos, Mario G. (Oxford University Press, 2015)
      Non-Gaussianity in the primordial fluctuations that seeded structure formation produces a signal in the galaxy power spectrum on very large scales. This signal contains vital information about the primordial Universe, but ...

    • Evolution of faint radio sources in the VIDEO-XMM3 field 

      McAlpine, K.; Jarvis, Matt; Bonfield, David G. (OUP, 2013)
      It has been speculated that low luminosity radio-loud AGN have the potential to serve as an important source of AGN feedback, and may be responsible for suppressing star-formation activity in massive elliptical galaxies ...